First generation antipsychotics, known as typical antipsychotics, were discovered in the 1950s. Most second generation drugs, called atypical antipsychotics, have been developed more recently. The first atypical antipsychotic, clozapine, was discovered in the 1950s and introduced clinically in the 1970s. Both generations of medication tend to block receptors in the brain's dopamine pathways; atypicals tend to act on serotonin receptors as well.

Notable and relatively common adverse effects of antipsychotics include extrapyramidal symptoms (which involve motor control and are very serious), hyperprolactinaemia (primarily in typicals), weight gain and metabolic abnormalities (mostly in atypicals).[2]